Cecile Perrin

Does life history predict past and current connectivity for rocky intertidal invertebrates across a marine biogeographic barrier

The southeast Australian coast potentially includes a complex biogeographic barrier, largely lacking exposed rocky shore that may limit the dispersal of rocky intertidal taxa and contribute to the maintenance of two biogeographic regions. Surprisingly, within the 300‐km barrier region, several species considered exposed rocky shore specialists occurred within sheltered sites. We analysed COI sequence variation for 10 rocky intertidal invertebrate species, with a range of life histories, to test the hypotheses that larval type and habitat specificity are strong predictors of gene flow between biogeographic regions. Our data revealed that the southeast corner of Australia includes a strong barrier to gene flow for six of eight species with planktonic larvae, and a coalescence analysis of sequence differentiation (IM model) suggests that a barrier has existed since the Pleistocene. In contrast, two direct developers were not affected by the barrier. Our comparative approach and data from earlier studies (reviewed here) do not support the hypothesis that larval type predicts gene flow across this barrier, instead we found that the ability to utilize sheltered habitat provides a clearer explanation of the phylogeographic break. Indeed, the species that displayed little or no evidence of a phylogeographic break across the barrier each displayed unexpectedly relaxed habitat specificity.

Implications of mating system for genetic diversity of sister algal species: Fucus spiralis and Fucus vesiculosus (Heterokontophyta, Phaeophyceae)

The implications of mating system for genetic diversity were assessed in the sister species Fucus spiralis and Fucus vesiculosus using a combination of ten microsatellite markers. Five new microsatellite markers specific for F. spiralis were developed in order to increase marker resolution and complement the results (i.e. mating system and genetic diversity extended to a larger geographic scale) acquired using five microsatellite loci previously developed from a mixed fucoid seaweed DNA library that excluded F. spiralis. Low genetic diversities observed at the population and species level in F. spiralis using the five new F. spiralis-specific loci described here were consistent with the results obtained previously with non-specific microsatellite loci. Results revealed that selfing is characteristic in F. spiralis across its latitudinal distribution along the Iberian and French Atlantic coasts. Higher levels of within-population genetic diversity were observed in the outcrossing species F. vesiculosus, decreasing towards the southern distributional range of the species. Some cases of significant biparental inbreeding in this species are indicative of short gamete dispersal or mating of spatially or temporally structured populations. In contrast to within-population diversities, higher total genetic diversity among populations was observed in the hermaphroditic species in comparison to the dioecious F. vesiculosus.

Climate-driven range shifts explain the distribution of extant gene pools and predict future loss of unique lineages in a marine brown alga

The climate‐driven dynamics of species ranges is a critical research question in evolutionary ecology. We ask whether present intraspecific diversity is determined by the imprint of past climate. This is an ongoing debate requiring interdisciplinary examination of population genetic pools and persistence patterns across global ranges. Previously, contrasting inferences and predictions have resulted from distinct genomic coverage and/or geographical information. We aim to describe and explain the causes of geographical contrasts in genetic diversity and their consequences for the future baseline of the global genetic pool, by comparing present geographical distribution of genetic diversity and differentiation with predictive species distribution modelling (SDM) during past extremes, present time and future climate scenarios for a brown alga, Fucus vesiculosus. SDM showed that both atmospheric and oceanic variables shape the global distribution of intertidal species, revealing regions of persistence, extinction and expansion during glacial and postglacial periods. These explained the distribution and structure of present genetic diversity, consisting of differentiated genetic pools with maximal diversity in areas of long‐term persistence. Most of the present species range comprises postglacial expansion zones and, in contrast to highly dispersive marine organisms, expansions involved only local fronts, leaving distinct genetic pools at rear edges. Besides unravelling a complex phylogeographical history and showing congruence between genetic diversity and persistent distribution zones, supporting the hypothesis of niche conservatism, range shifts and loss of unique genetic diversity at the rear edge were predicted for future climate scenarios, impoverishing the global gene pool.

A SIGNIFICANT COMPONENT OF AGEING (DNA DAMAGE) IS REFLECTED IN FADING BREEDING COLORS: AN EXPERIMENTAL TEST USING INNATE ANTIOXIDANT MIMETICS IN PAINTED DRAGON LIZARDS

A decade ahead of their time, von Schantz et al. united sexual selection and free radical biology by identifying causal links between deep‐rooted physiological processes that dictate resistance to toxic waste from oxidative metabolism (reactive oxygen species, ROS), and phenotypic traits, such as ornaments. Ten years later, these ideas have still only been tested with indirect estimates of free radical levels (oxidative stress) subsequent to the action of innate and dietary antioxidants. Here, we measure net superoxide (a selection pressure for antioxidant production) and experimentally manipulate superoxide antioxidation using a synthetic mimetic of superoxide dismutase (SOD), Eukarion 134 (EUK). We then measure the toxic effect of superoxide in terms of DNA erosion and concomitant loss of male breeding coloration in the lizard, Ctenophorus pictus. Control males suffered more DNA damage than EUK males. Spectroradiometry showed that male coloration is lost in relation to superoxide and covaries with DNA erosion; in control males, these variables explained loss of color, whereas in EUK males, the fading of coloration was unaffected by superoxide and unrelated to DNA damage. Thus, EUKs powerful antioxidation removes the erosion effect of superoxide on coloration and experimentally verifies the prediction that colors reflect innate capacity for antioxidation.

Effects of spending time outdoors in daylight on the psychosocial well-being of older people and their family carers: a systematic review

Background A range of studies found that spending time outdoors in daylight provided substantial benefits for the psychosocial well‐being of older people. Good psychosocial well‐being is essential in maintaining overall health as people age and often contributes to adequate physical functioning. Objectives The overall objective of this study was to undertake a systematic review on the effects of spending time outdoors in daylight on the psychosocial well‐being of older people and their family carers. Inclusion criteria Types of participants This review considered studies that included older people aged 55 years or more, including those living in a community or residential accommodation setting. In addition, this review considered family carers, who were defined as unpaid relatives or friends of an older person, who helped that individual with their activities of daily living. Types of intervention(s) The intervention of interest was spending time outdoors in daylight. Types of studies All experimental and epidemiological study designs including randomized controlled trials and non‐randomized controlled trials published in the English language were included in this review. Types of outcomes This review considered studies that included objective and/or subjective measures of psychosocial well‐being for older people and their family carers. Search strategy The search aimed to find published and unpublished studies through electronic databases, reference lists, key reports and the World Wide Web. An extensive search was undertaken for the following databases: MEDLINE, CINAHL, Wiley Online Library, ProQuest Central, Scopus, and the Cochrane Library. Databases were searched up to December 2013. Methodological quality Methodological quality was assessed independently by three reviewers using the Joanna Briggs Institute Meta‐Analysis of Statistics Assessment and Review Instrument (JBI‐MAStARI) checklists. Disagreements that arose between the reviewers were resolved through discussion. Data collection Quantitative data were extracted from papers included in the review using the standardized data extraction tool from JBI‐MAStARI. The data was individually extracted by two reviewers. Disagreements that arose between the reviewers were resolved through discussion. All results were subject to double data entry. Data synthesis For this review statistical pooling of the data was not possible due to the heterogeneity of the studies; therefore, the findings are presented in narrative form. Results A total of 13 studies were included in the final review. In the four studies that evaluated the effects of exposure to daylight on behavioral disturbances, there was no evidence of effect of daylight hours on physical and verbal aggression. There was some evidence to indicate that exposure to daylight for a period of time resulted in fewer depressive symptoms. Increasing the frequency of going outdoors was associated with better cognitive preservation over a one year period. Similarly exposure to daylight resulted in improved social functioning and improved quality of life. There were no studies that evaluated the effect of spending time outdoors in daylight on the psychosocial well‐being of family carers, including carer satisfaction or carer stress. Conclusions There is insufficient high‐quality evidence from which conclusions can be drawn for the effect of spending time outdoors in daylight on the psychosocial well‐being of older people and their family carers. More robust research is required to evaluate the effectiveness of interventions to improve time spent outdoors in daylight for older people and their family carers. Implications for practice There is some evidence to support the effects of exposure to daylight on mood, cognition and social functioning levels. With only small changes in routines for nursing staff there is potential for exposure to sunlight to have a significant impact on psychosocial well‐being for older adults living in residential accommodation. Implications for research Future studies should be undertaken using more rigorous research designs, such as randomized controlled trials with sufficiently powered sample sizes. A focus on accurately measuring time spent outdoors in daylight should be a priority. Additionally, by investigating a comprehensive range of psychosocial outcomes with validated tools, researchers could more accurately deduce the effect of spending time outdoors on the psychosocial well‐being of older people and family carers.

Complex selection associated with Hox genes in a natural population of lizards

Hox genes are recognized for their explanatory power of bilateral development. However, relatively little is known about natural variation in, and the evolutionary dynamics of, Hox genes within wild populations. Utilizing a natural population of sand lizards (Lacerta agilis), we screened HoxA13 for genetic variation and an association with incidence of offspring malformations. We found significant effects of parental genetic similarity and offspring sex, and their interaction, on risk of hatching malformed as an offspring. We also found within population genetic variation in HoxA13, and identified a significant effect of a three‐way interaction among Hox genotype, parental genetic similarity, and offspring sex on the risk of hatching malformation. Since malformed offspring in this population do not survive to maturity, this study reveals complex and ongoing selection associated with Hox genes in a wild reptile population. Importantly, this demonstrates the utility of natural populations in unveiling microevolutionary processes shaping variation in highly conserved genes.